How do I filter elements from a sequence based on indexes

Question

I have a sequence s and a list of indexes into this sequence indexes. How do I retain only the items given via the indexes?

Simple example:

Answer 1

=> (defn filter-by-index [src indexes]
     (reduce (fn [a i] (conj a (nth src i))) [] indexes))

=> (filter-by-index '(a b c d e f g) '(0 2 3 4))
[a c d e]